1. Field of the Invention
The present invention relates to a disk device and particularly relates to a load/unload-type hard disk device including a carriage arm with a load bar at its tip and a ramp member provided on a chassis base for supporting the load bar.
2. Description of the Related Art
Hard disk devices magnetically store information and are typically installed in computer machines. Among various types of computer machines, a portable notebook-type computer machine is often subjected to unintended impact because a user may drop it or hit it against an object. Therefore, a highly shock-resistant structure is required for notebook-type computer machines.
Hard disk devices to be installed in notebook-type computer machines are required to have improved shock-resistance compared to hard disk devices to be installed in desktop-type computer machines.
There are two types of hard disk devices when categorized according to the position of a slider in a stop mode. One is a contact-start-stop type where the slider is held above an inner periphery side of the hard disk and another is a load-unload type where the slider is retracted to a position outside the periphery of the hard disk. The load-unload type hard disk device includes a load bar provided at a tip of a carriage arm and a ramp member provided on a chassis base for supporting the load bar. When the slider is retracted to a position outside the periphery of the hard disk, the ramp member supports the load bar. In other words, the slider is supported by the ramp member via the load bar. Here, the term xe2x80x9cunloadingxe2x80x9d is to be understood as an operation in which the slider positioned above the hard disk is retracted to a position outside the periphery of the hard disk. The term xe2x80x9cloadingxe2x80x9d is to be understood as an operation in which the slider at a position outside the periphery of the hard disk is moved to a position above the hard disk.
Generally, in terms of shock resistance, the load-unload type hard disk device is more reliable compared to the contact-start-stop type hard disk device. Therefore, the notebook-type computer devices are often installed with the load-unload type hard disk devices.
FIGS. 1A and 1B are a plan view and a side view, respectively, showing a hard disk device of the related art in an unloaded state where the slider is retracted to a position outside a hard disk 10. The hard disk 10 is rotated at a high speed in a direction shown by an arrow A. A ramp member 11 is a molded component made of synthetic resin and is screwed on a chassis base (not shown) of the hard disk device at a position outside the hard disk 10. An upper load bar 12, a lower load bar 13, an upper slider 14 and a lower slider 15 are also shown in the figures. Magnetic heads are provided in side surfaces of each of the sliders 14 and 15. A carriage arm 16 is also shown. When the carriage arm 16 is pivotally moved by a voice-coil-motor-type actuator (not shown), the load bars 12, 13 and the sliders 14, 15 are moved in the directions shown by a double-headed arrow B1, B2.
As shown in FIGS. 2 and 1B, the ramp member 11 is provided with a trapezoidal guiding part 20 and a parking part 21 for the upper load bar 12 and a trapezoidal guiding part 22 and a parking part 23 for the lower load bar 13.
The parking parts 21, 23 have smooth surfaces so that the load bars 12, 13 can be moved smoothly.
The guiding parts 20, 22 include hard disk (HD) side ramp surfaces 20a, 22a closer to the hard disk 10, parking part-side ramp surfaces 20b, 22b adjacent the parking parts and intermediate surfaces 20c, 22c between the HD-side and parking part side ramp surfaces, respectively. All surfaces are made smooth for smooth movements of the load bars 12, 13. The parking part-side ramp surfaces 20b, 22b are substantially at the same position in the B1-B2 direction.
When an unload command is supplied during read/write operation, the carriage arm 16 is pivoted in a clockwise direction. The load bars 12, 13 are moved over the guiding parts 20, 22 until they reach the parking parts 21, 23. The hard disk device is now in an unloaded state as shown in FIGS. 1A and 1B. When a load command is supplied during the unloaded state, the carriage arm 16 is pivoted in an anti-clockwise direction. The load bars 12, 13 are moved over the guiding parts 20, 22 for implementing a loading operation. The sliders 14, 15 are loaded above the hard disk 10 and are held against an upper surface 10a and a lower surface 10b of the rotating hard disk 10. Then, the read/write operation of information is initiated.
As shown in FIG. 1B, the load bars 12, 13 move along broken lines 30, 31, respectively, and the sliders 14, 15 move along broken lines 32, 33, respectively.
Each time an unload/load operation is implemented, the load bars 12, 13 slide on the guiding parts 20, 22 and the parking parts 21, 23 of the ramp member 11. When such sliding operations are repeated frequently, the ramp member 11 is abrased and unwanted powder of abrased material is produced. The powder then attaches to the load bars 12, 13 and eventually falls off from the load bars 12, 13.
If the powder falls off from the load bars 12, 13 while the sliders 14, 15 are loaded above the hard disk 10, the powder will fall onto the hard disk 10. If the powder intrudes between the hard disk 10 and the sliders 14, 15 held against the hard disk 10, a head crash occurs and a recording surface of the hard disk 10 may be damaged.
During the loading operation, the load bars 12, 13 ascend the parking part-side ramp surfaces 20b, 22b, respectively. The load bars 12, 13 ascend at the same timings. Accordingly, a considerably great load must be applied to the actuator (not shown) and thus a considerable amount of electric current is required for driving the actuator. Therefore, the power consumption of the hard disk device becomes even higher.
The load applied to the actuator during loading operation becomes higher as the number of hard disks 10 installed in the hard disk device, the number of the sliders and the number of the load bars increase. Accordingly, more electric current is required for driving the actuator and thus the consumption power of the hard disk device increases.
Since such a hard disk device is installed in a notebook-type personal computer and is driven by a battery mounted in the notebook-type personal computer, there is a need for a hard disk device operable with reduced power consumption.
Accordingly, it is a general object of the present invention to provide a hard disk device which can satisfy the need described above.
It is another and more specific object of the present invention to provide a hard disk device which can prevent the powder on the load bar from being dropped on the surface of hard disks.
In order to achieve the above object, a disk device is provided which includes:
a chassis base;
at least one disk rotatably supported on the chassis base;
at least one carriage arm pivotable about an axis on one end and, at the other end, having a slider with a read/write head and a load bar extending from the slider;
a ramp member attached to the chassis base at a position outside the disk, the ramp member having a guiding part and a parking part; and
an actuator for driving the carriage arm between a loaded position in which the slider is held above the disk and an unloaded position in which the load bar rests on the parking part of the ramp member,
wherein the ramp member is provided with cleaning means for removing powder attached to the load bar as the load bar moves along the parking part.
With the above invention, an occurrence of head crash due to powder can be effectively avoided.
It is still another object of the invention to provide a hard disk device which can disperse the load applied to the actuator during a loading operation.
In order to achieve the above object, a disk device is provided which includes:
a chassis base;
at least one disk rotatably supported on the chassis base;
at least two carriage arms pivotable about an axis on one end and, at the other end, having a slider with a read/write head and a load bar extending from the slider;
a ramp member attached to the chassis base at a position outside the disk, the ramp member having a guiding part and a parking part;
an actuator for driving the carriage arms between a loaded position in which the slider is held above the disk and an unloaded position in which the load bar rests on the parking part of the ramp member; and
timing offsetting means for offsetting the timing of the load bar of one of the carriage arms ascending the guiding part from the timing of the load bar of one of the other carriage arms ascending the guiding part when the carriage arms are driven to move from the unloaded position to the loaded position.
With the above invention, the maximum value of the current required for driving the actuator is reduced.